Metabolism & Carbohydrate Pathways – Vocabulary Drill

Allosteric protein

Regulated by remote binding.

Allosteric site

Non-active regulatory pocket.

Allosteric activator

Stabilizes R state.

Allosteric inhibitor

Stabilizes T state.

Conformational change

Shape shift altering activity.

Quaternary structure

Multisubunit protein assembly.

R state

Active relaxed conformation.

T state

Inactive tense conformation.

Metabolic flux

Pathway reaction rate.

Anabolism

Energy-requiring biosynthesis.

Catabolism

Energy-releasing degradation.

ATP

Cellular energy currency.

ATP hydrolysis

Releases large ΔG.

Phosphoryl-transfer potential

Ability to donate phosphate.

Electrostatic repulsion

Strain between ATP phosphates.

Resonance stabilization

Delocalized product electrons.

Solvation energy

Stabilizing water interactions.

Endergonic reaction

Requires energy input.

Exergonic reaction

Releases free energy.

Redox reaction

Electron transfer process.

Oxidation

Electron loss.

Reduction

Electron gain.

NAD⁺

Oxidized electron carrier.

NADH

Reduced electron carrier.

FAD

Oxidized flavin carrier.

FADH₂

Reduced flavin carrier.

Electron transport chain

Mitochondrial redox series.

Fuel value

Energy yield on oxidation.

Hydrocarbon

Reduced carbon chain.

Flux control

Regulation of pathway speed.

Hexokinase

Glycolysis step-1 enzyme.

Phosphofructokinase-1

Glycolysis rate-limiter.

Pyruvate kinase

Final glycolysis enzyme.

Glycolysis

Glucose → pyruvate pathway.

ΔG

Gibbs free energy change.

Irreversible step

Large negative ΔG.

Reversible step

ΔG near zero.

Isomerization

Structural rearrangement reaction.

Phosphorylation

Phosphate group addition.

ATP coupling

Driving endergonic reactions.

NAD⁺ reduction

Electron acceptance forming NADH.

Substrate-level phosphorylation

Direct ADP phosphorylation.

1,3-BPG

High-energy glycolytic intermediate.

PEP

Phosphoenolpyruvate; high energy.

Gluconeogenesis

Pyruvate → glucose synthesis.

Glucose-6-phosphatase

GNG final enzyme.

FBPase-1

Fructose bisphosphatase enzyme.

PEPCK

Converts OAA → PEP.

AMP

Low-energy signal.

Citrate

TCA intermediate, inhibitor.

Biotin

CO₂ carrier coenzyme.

Pyruvate carboxylase

Forms oxaloacetate.

Insulin

Anabolic pancreatic hormone.

Glucagon

Catabolic pancreatic hormone.

PFK2

Makes F2,6BP.

FBPase2

Degrades F2,6BP.

Fructose-2,6-bisphosphate

Potent PFK-1 activator.

Signal transduction

External cue conversion.

Receptor tyrosine kinase

Insulin receptor type.

IRS

Insulin receptor substrate.

PI3K

Phosphoinositide kinase.

Akt

Ser/Thr kinase effector.

GLUT4

Insulin-responsive glucose transporter.

Kinase

Adds phosphate groups.

Phosphatase

Removes phosphate groups.

Type I diabetes

Insulin deficiency disorder.

Hyperglycemia

Elevated blood glucose.

Cytosol

Glycolysis location.

Mitochondrial matrix

TCA and PDH site.

Pyruvate

Glycolysis end product.

Acetyl-CoA

TCA entry molecule.

Lactate

Anaerobic pyruvate product.

Ethanol

Yeast anaerobic product.

Pyruvate dehydrogenase

Converts pyruvate to acetyl-CoA.

TCA cycle

Central oxidative pathway.

Isocitrate dehydrogenase

Key TCA enzyme.

α-Ketoglutarate dehydrogenase

Produces succinyl-CoA.

Citrate synthase

Condenses OAA + acetyl-CoA.

Succinate dehydrogenase

Complex II enzyme.

Anaplerosis

TCA intermediate replenishment.

Oxaloacetate

Four-carbon TCA acceptor.

Proton motive force

ΔΨ + ΔpH energy.

Complex I

NADH dehydrogenase.

Complex III

Cytochrome bc₁ complex.

Complex IV

Cytochrome oxidase.

Coenzyme Q

Lipid electron shuttle.

Cytochrome c

Soluble electron carrier.

ATP synthase

Proton-driven ATP maker.

Chemiosmosis

Proton gradient utilization.

Aerobic respiration

O₂-dependent ATP production.

Anaerobic metabolism

Without oxygen energy.

Oxidative phosphorylation

ETC-linked ATP synthesis.

Redox potential

Electron affinity measure.

Water formation

O₂ reduction product.

Glucose oxidation

Generates ~30 ATP.

Complex II

FADH₂ entry point.

Inner mitochondrial membrane

ETC location.

Intermembrane space

Proton accumulation site.

Matrix

ATP formed here.

Proton pump

Moves H⁺ across membrane.